Abstract
•We study the effects of central barrier on the current-density and transmission coefficient in double-barrier and triple-barrier RTD.•The obtained results show that the double-barrier RTD produced a higher current density than the triple-barrier RTD.•It is found that in the triple-barrier RTD, the maximum current was obtained for lower applied bias compared to the double-barrier RTD.
In this paper, we investigated the effect of the central AlGaAs barrier width Lb2 in a resonant tunneling diode (RTD) composed by triple barriers on the current-voltage characteristics, and electronic density of free carriers. In addition, this is a comparative study on the current-voltage characteristics that are produced by a double-barriers and triple-barriers RTD. Our simulation was performed using a non-equilibrium Green’s formalism (NEGF). The results showed that the double-barrier RTD produced a higher current density than the triple-barrier RTD. However, in the triple-barrier RTD, the maximum current was obtained for lower applied bias compared to the double-barrier RTD. The peak to valley current ratio (PVCR) has been evaluated and our results indicate that the double-barrier RTD can produces a higher ratio values compared to those produced by triple-barrier RTD. Our findings also showed that for the triple-barrier RTD, the negative differential resistance (NDR) depended on the width Lb2 of the central barrier. By reducing Lb2, the NDR decreased dramatically and disappeared completely for Lb2 = 3 nm. These results open the door for designing a double and triple-barrier RTD with suitable negative differential resistances. The RTD simulation was performed using the Nanohub tool, which confirms the various results presented in this paper.